Over one-third the volume of in-the-body heart defibrillators is devoted to the capacitor, which consumes approximately 20 cm3; this volume could be reduced to less than 1 cm3 using proven integrated circuit technology. Employing metalorganic chemical vapor deposition (MOCVD), Spire proposes to form thin film ceramic capacitors having at least a hundred times greater energy density than is presently available from commercial products. MOCVD makes this possible by eliminating the voids and other field enhancing defects which limit capacitor performance. Spire's capacitors will be barium-strontium-titanate-based and will feature extremely high dielectric constant (over 1,000) and breakdown strength (100 V/micromoles). In Phase I, a single-layer 1 mu F, 1000 V capacitor will be fabricated and demonstrated as proof-of-principle that full-sized prototype capacitors can be built in Phase Il, where they would be made available to manufacturers of defibrillators for testing. Successful completion of the proposed program will lead to immediate introduction of smaller devices with improved patient comfort.